docs: def feature_assert(*feas):
      """
      Takes some feature patterns (like in `feature_needs`).
      Raises a fuse.FuseError if your underlying FUSE lib fails
      to have some of the matching features.
  
      (Note: use a ``has_foo`` type feature assertion only if lib support
      for method ``foo`` is *necessary* for your fs. Don't use this assertion
      just because your fs implements ``foo``. The usefulness of ``has_foo``
      is limited by the fact that we can't guarantee that your FUSE kernel
      module also supports ``foo``.)
      """
  
      fav = APIVersion()
  
      for fea in feas:
          fn = feature_needs(fea)
          if fav < fn:
              raise FuseError(
                "FUSE API version %d is required for feature `%s' but only %d is available" % \
                (fn, str(fea), fav))